This invention relates to a profile rail for affixing a flexible, sheetlike structure, such as a screen, a canvas or a foil, onto a substantially flat carrier in the shape of a frame or plate, said rail having a substantially U-shaped cross section and teeth or projections and being attachable to said carrier.
An extendible frame for painting canvas is already known which comprises a U-rail of this general kind (U.S. Pat. No. 3,529,653). This rail of the prior art which is intended to be clamped around one shank of an angle iron, around which the canvas is stretched, outside the latter, has the inside of its inner shank provided with teeth which penetrate into the canvas being clamped by means of the rail. The canvas and the rail are clamped on to the shank of the angle iron by means of an outer, stiffer rail which embraces the canvas and the rail and also has a U-shaped cross section. This known structure is comparatively complex since double rails are required. In addition thereto the fastening of the canvas is intricate, since it has to be grasped and held by hand while being fastened. In addition thereto it is almost impossible, on account of the saw-tooth shape of the teeth, to remove the fastened canvas without tearing it.